The immigrant population increased by 32 million in 37 European countries from 1990-2019. Much of this movement was internal, from east to west Europe. Although both the destination and origin countries could be affected, we find no effects on aggregate subjective well-being in either group, using country-panel and instrumental variable techniques. Immigrants, in contrast, experienced increased well-being, converted to monetary terms, in excess of £25,000 per person. We offer more comprehensive evidence than previous studies, in terms of country and period, and by assessing the impacts on subjective well-being, which captures all of the important factors affected by immigration.